#ifndef BCM_C
// do nothing
#elif defined BCM_NO_ENCODER
// dummy
int bcm_divbwt(const unsigned char *T, unsigned char *U, int *A, int n) { return -1; }
#else
/*
 * divsufsort.h for libdivsufsort-lite
 * Copyright (c) 2003-2008 Yuta Mori All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef _DIVSUFSORT_H
#define _DIVSUFSORT_H 1

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */


/*- Prototypes -*/

/**
 * Constructs the suffix array of a given string.
 * @param T[0..n-1] The input string.
 * @param SA[0..n-1] The output array of suffixes.
 * @param n The length of the given string.
 * @return 0 if no error occurred, -1 or -2 otherwise.
 */
int
bcm_divsufsort(const unsigned char *T, int *SA, int n);

/**
 * Constructs the burrows-wheeler transformed string of a given string.
 * @param T[0..n-1] The input string.
 * @param U[0..n-1] The output string. (can be T)
 * @param A[0..n-1] The temporary array. (can be NULL)
 * @param n The length of the given string.
 * @return The primary index if no error occurred, -1 or -2 otherwise.
 */
int
bcm_divbwt(const unsigned char *T, unsigned char *U, int *A, int n);


#ifdef __cplusplus
} /* extern "C" */
#endif /* __cplusplus */

#endif /* _DIVSUFSORT_H */

/*
 * divsufsort.c for libdivsufsort-lite
 * Copyright (c) 2003-2008 Yuta Mori All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef _OPENMP
# include <omp.h>
#endif
//#include "bcm_divsufsort.h"


/*- Constants -*/
#define INLINE __inline
#if defined(ALPHABET_SIZE) && (ALPHABET_SIZE < 1)
# undef ALPHABET_SIZE
#endif
#if !defined(ALPHABET_SIZE)
# define ALPHABET_SIZE (256)
#endif
#define BUCKET_A_SIZE (ALPHABET_SIZE)
#define BUCKET_B_SIZE (ALPHABET_SIZE * ALPHABET_SIZE)
#if defined(SS_INSERTIONSORT_THRESHOLD)
# if SS_INSERTIONSORT_THRESHOLD < 1
#  undef SS_INSERTIONSORT_THRESHOLD
#  define SS_INSERTIONSORT_THRESHOLD (1)
# endif
#else
# define SS_INSERTIONSORT_THRESHOLD (8)
#endif
#if defined(SS_BLOCKSIZE)
# if SS_BLOCKSIZE < 0
#  undef SS_BLOCKSIZE
#  define SS_BLOCKSIZE (0)
# elif 32768 <= SS_BLOCKSIZE
#  undef SS_BLOCKSIZE
#  define SS_BLOCKSIZE (32767)
# endif
#else
# define SS_BLOCKSIZE (1024)
#endif
/* minstacksize = log(SS_BLOCKSIZE) / log(3) * 2 */
#if SS_BLOCKSIZE == 0
# define SS_MISORT_STACKSIZE (96)
#elif SS_BLOCKSIZE <= 4096
# define SS_MISORT_STACKSIZE (16)
#else
# define SS_MISORT_STACKSIZE (24)
#endif
#define SS_SMERGE_STACKSIZE (32)
#define TR_INSERTIONSORT_THRESHOLD (8)
#define TR_STACKSIZE (64)


/*- Macros -*/
#ifndef SWAP
# define SWAP(_a, _b) do { t = (_a); (_a) = (_b); (_b) = t; } while(0)
#endif /* SWAP */
#ifndef MIN
# define MIN(_a, _b) (((_a) < (_b)) ? (_a) : (_b))
#endif /* MIN */
#ifndef MAX
# define MAX(_a, _b) (((_a) > (_b)) ? (_a) : (_b))
#endif /* MAX */
#define STACK_PUSH(_a, _b, _c, _d)\
    do {\
        assert(ssize < STACK_SIZE);\
        stack[ssize].a = (_a), stack[ssize].b = (_b),\
        stack[ssize].c = (_c), stack[ssize++].d = (_d);\
    } while(0)
#define STACK_PUSH5(_a, _b, _c, _d, _e)\
    do {\
        assert(ssize < STACK_SIZE);\
        stack[ssize].a = (_a), stack[ssize].b = (_b),\
        stack[ssize].c = (_c), stack[ssize].d = (_d), stack[ssize++].e = (_e);\
    } while(0)
#define STACK_POP(_a, _b, _c, _d)\
    do {\
        assert(0 <= ssize);\
        if(ssize == 0) { return; }\
        (_a) = stack[--ssize].a, (_b) = stack[ssize].b,\
        (_c) = stack[ssize].c, (_d) = stack[ssize].d;\
    } while(0)
#define STACK_POP5(_a, _b, _c, _d, _e)\
    do {\
        assert(0 <= ssize);\
        if(ssize == 0) { return; }\
        (_a) = stack[--ssize].a, (_b) = stack[ssize].b,\
        (_c) = stack[ssize].c, (_d) = stack[ssize].d, (_e) = stack[ssize].e;\
    } while(0)
#define BUCKET_A(_c0) bucket_A[(_c0)]
#if ALPHABET_SIZE == 256
#define BUCKET_B(_c0, _c1) (bucket_B[((_c1) << 8) | (_c0)])
#define BUCKET_BSTAR(_c0, _c1) (bucket_B[((_c0) << 8) | (_c1)])
#else
#define BUCKET_B(_c0, _c1) (bucket_B[(_c1) * ALPHABET_SIZE + (_c0)])
#define BUCKET_BSTAR(_c0, _c1) (bucket_B[(_c0) * ALPHABET_SIZE + (_c1)])
#endif


/*- Private Functions -*/

static const int lg_table[256]= {
 -1,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
    5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};

#if (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE)

static INLINE
int
ss_ilg(int n) {
#if SS_BLOCKSIZE == 0
    return (n & 0xffff0000) ?
                    ((n & 0xff000000) ?
                        24 + lg_table[(n >> 24) & 0xff] :
                        16 + lg_table[(n >> 16) & 0xff]) :
                    ((n & 0x0000ff00) ?
                         8 + lg_table[(n >>  8) & 0xff] :
                         0 + lg_table[(n >>  0) & 0xff]);
#elif SS_BLOCKSIZE < 256
    return lg_table[n];
#else
    return (n & 0xff00) ?
                    8 + lg_table[(n >> 8) & 0xff] :
                    0 + lg_table[(n >> 0) & 0xff];
#endif
}

#endif /* (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE) */

#if SS_BLOCKSIZE != 0

static const int sqq_table[256] = {
    0,  16,  22,  27,  32,  35,  39,  42,  45,  48,  50,  53,  55,  57,  59,  61,
 64,  65,  67,  69,  71,  73,  75,  76,  78,  80,  81,  83,  84,  86,  87,  89,
 90,  91,  93,  94,  96,  97,  98,  99, 101, 102, 103, 104, 106, 107, 108, 109,
110, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
128, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142,
143, 144, 144, 145, 146, 147, 148, 149, 150, 150, 151, 152, 153, 154, 155, 155,
156, 157, 158, 159, 160, 160, 161, 162, 163, 163, 164, 165, 166, 167, 167, 168,
169, 170, 170, 171, 172, 173, 173, 174, 175, 176, 176, 177, 178, 178, 179, 180,
181, 181, 182, 183, 183, 184, 185, 185, 186, 187, 187, 188, 189, 189, 190, 191,
192, 192, 193, 193, 194, 195, 195, 196, 197, 197, 198, 199, 199, 200, 201, 201,
202, 203, 203, 204, 204, 205, 206, 206, 207, 208, 208, 209, 209, 210, 211, 211,
212, 212, 213, 214, 214, 215, 215, 216, 217, 217, 218, 218, 219, 219, 220, 221,
221, 222, 222, 223, 224, 224, 225, 225, 226, 226, 227, 227, 228, 229, 229, 230,
230, 231, 231, 232, 232, 233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 238,
239, 240, 240, 241, 241, 242, 242, 243, 243, 244, 244, 245, 245, 246, 246, 247,
247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 253, 254, 254, 255
};

static INLINE
int
ss_isqrt(int x) {
    int y, e;

    if(x >= (SS_BLOCKSIZE * SS_BLOCKSIZE)) { return SS_BLOCKSIZE; }
    e = (x & 0xffff0000) ?
                ((x & 0xff000000) ?
                    24 + lg_table[(x >> 24) & 0xff] :
                    16 + lg_table[(x >> 16) & 0xff]) :
                ((x & 0x0000ff00) ?
                     8 + lg_table[(x >>  8) & 0xff] :
                     0 + lg_table[(x >>  0) & 0xff]);

    if(e >= 16) {
        y = sqq_table[x >> ((e - 6) - (e & 1))] << ((e >> 1) - 7);
        if(e >= 24) { y = (y + 1 + x / y) >> 1; }
        y = (y + 1 + x / y) >> 1;
    } else if(e >= 8) {
        y = (sqq_table[x >> ((e - 6) - (e & 1))] >> (7 - (e >> 1))) + 1;
    } else {
        return sqq_table[x] >> 4;
    }

    return (x < (y * y)) ? y - 1 : y;
}

#endif /* SS_BLOCKSIZE != 0 */


/*---------------------------------------------------------------------------*/

/* Compares two suffixes. */
static INLINE
int
ss_compare(const unsigned char *T,
                     const int *p1, const int *p2,
                     int depth) {
    const unsigned char *U1, *U2, *U1n, *U2n;

    for(U1 = T + depth + *p1,
            U2 = T + depth + *p2,
            U1n = T + *(p1 + 1) + 2,
            U2n = T + *(p2 + 1) + 2;
            (U1 < U1n) && (U2 < U2n) && (*U1 == *U2);
            ++U1, ++U2) {
    }

    return U1 < U1n ?
                (U2 < U2n ? *U1 - *U2 : 1) :
                (U2 < U2n ? -1 : 0);
}


/*---------------------------------------------------------------------------*/

#if (SS_BLOCKSIZE != 1) && (SS_INSERTIONSORT_THRESHOLD != 1)

/* Insertionsort for small size groups */
static
void
ss_insertionsort(const unsigned char *T, const int *PA,
                                 int *first, int *last, int depth) {
    int *i, *j;
    int t;
    int r;

    for(i = last - 2; first <= i; --i) {
        for(t = *i, j = i + 1; 0 < (r = ss_compare(T, PA + t, PA + *j, depth));) {
            do { *(j - 1) = *j; } while((++j < last) && (*j < 0));
            if(last <= j) { break; }
        }
        if(r == 0) { *j = ~*j; }
        *(j - 1) = t;
    }
}

#endif /* (SS_BLOCKSIZE != 1) && (SS_INSERTIONSORT_THRESHOLD != 1) */


/*---------------------------------------------------------------------------*/

#if (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE)

static INLINE
void
ss_fixdown(const unsigned char *Td, const int *PA,
                     int *SA, int i, int size) {
    int j, k;
    int v;
    int c, d, e;

    for(v = SA[i], c = Td[PA[v]]; (j = 2 * i + 1) < size; SA[i] = SA[k], i = k) {
        d = Td[PA[SA[k = j++]]];
        if(d < (e = Td[PA[SA[j]]])) { k = j; d = e; }
        if(d <= c) { break; }
    }
    SA[i] = v;
}

/* Simple top-down heapsort. */
static
void
ss_heapsort(const unsigned char *Td, const int *PA, int *SA, int size) {
    int i, m;
    int t;

    m = size;
    if((size % 2) == 0) {
        m--;
        if(Td[PA[SA[m / 2]]] < Td[PA[SA[m]]]) { SWAP(SA[m], SA[m / 2]); }
    }

    for(i = m / 2 - 1; 0 <= i; --i) { ss_fixdown(Td, PA, SA, i, m); }
    if((size % 2) == 0) { SWAP(SA[0], SA[m]); ss_fixdown(Td, PA, SA, 0, m); }
    for(i = m - 1; 0 < i; --i) {
        t = SA[0], SA[0] = SA[i];
        ss_fixdown(Td, PA, SA, 0, i);
        SA[i] = t;
    }
}


/*---------------------------------------------------------------------------*/

/* Returns the median of three elements. */
static INLINE
int *
ss_median3(const unsigned char *Td, const int *PA,
                     int *v1, int *v2, int *v3) {
    int *t;
    if(Td[PA[*v1]] > Td[PA[*v2]]) { SWAP(v1, v2); }
    if(Td[PA[*v2]] > Td[PA[*v3]]) {
        if(Td[PA[*v1]] > Td[PA[*v3]]) { return v1; }
        else { return v3; }
    }
    return v2;
}

/* Returns the median of five elements. */
static INLINE
int *
ss_median5(const unsigned char *Td, const int *PA,
                     int *v1, int *v2, int *v3, int *v4, int *v5) {
    int *t;
    if(Td[PA[*v2]] > Td[PA[*v3]]) { SWAP(v2, v3); }
    if(Td[PA[*v4]] > Td[PA[*v5]]) { SWAP(v4, v5); }
    if(Td[PA[*v2]] > Td[PA[*v4]]) { SWAP(v2, v4); SWAP(v3, v5); }
    if(Td[PA[*v1]] > Td[PA[*v3]]) { SWAP(v1, v3); }
    if(Td[PA[*v1]] > Td[PA[*v4]]) { SWAP(v1, v4); SWAP(v3, v5); }
    if(Td[PA[*v3]] > Td[PA[*v4]]) { return v4; }
    return v3;
}

/* Returns the pivot element. */
static INLINE
int *
ss_pivot(const unsigned char *Td, const int *PA, int *first, int *last) {
    int *middle;
    int t;

    t = last - first;
    middle = first + t / 2;

    if(t <= 512) {
        if(t <= 32) {
            return ss_median3(Td, PA, first, middle, last - 1);
        } else {
            t >>= 2;
            return ss_median5(Td, PA, first, first + t, middle, last - 1 - t, last - 1);
        }
    }
    t >>= 3;
    first  = ss_median3(Td, PA, first, first + t, first + (t << 1));
    middle = ss_median3(Td, PA, middle - t, middle, middle + t);
    last   = ss_median3(Td, PA, last - 1 - (t << 1), last - 1 - t, last - 1);
    return ss_median3(Td, PA, first, middle, last);
}


/*---------------------------------------------------------------------------*/

/* Binary partition for substrings. */
static INLINE
int *
ss_partition(const int *PA,
                                        int *first, int *last, int depth) {
    int *a, *b;
    int t;
    for(a = first - 1, b = last;;) {
        for(; (++a < b) && ((PA[*a] + depth) >= (PA[*a + 1] + 1));) { *a = ~*a; }
        for(; (a < --b) && ((PA[*b] + depth) <  (PA[*b + 1] + 1));) { }
        if(b <= a) { break; }
        t = ~*b;
        *b = *a;
        *a = t;
    }
    if(first < a) { *first = ~*first; }
    return a;
}

/* Multikey introsort for medium size groups. */
static
void
ss_mintrosort(const unsigned char *T, const int *PA,
                            int *first, int *last,
                            int depth) {
#define STACK_SIZE SS_MISORT_STACKSIZE
    struct { int *a, *b, c; int d; } stack[STACK_SIZE];
    const unsigned char *Td;
    int *a, *b, *c, *d, *e, *f;
    int s, t;
    int ssize;
    int limit;
    int v, x = 0;

    for(ssize = 0, limit = ss_ilg(last - first);;) {

        if((last - first) <= SS_INSERTIONSORT_THRESHOLD) {
#if 1 < SS_INSERTIONSORT_THRESHOLD
            if(1 < (last - first)) { ss_insertionsort(T, PA, first, last, depth); }
#endif
            STACK_POP(first, last, depth, limit);
            continue;
        }

        Td = T + depth;
        if(limit-- == 0) { ss_heapsort(Td, PA, first, last - first); }
        if(limit < 0) {
            for(a = first + 1, v = Td[PA[*first]]; a < last; ++a) {
                if((x = Td[PA[*a]]) != v) {
                    if(1 < (a - first)) { break; }
                    v = x;
                    first = a;
                }
            }
            if(Td[PA[*first] - 1] < v) {
                first = ss_partition(PA, first, a, depth);
            }
            if((a - first) <= (last - a)) {
                if(1 < (a - first)) {
                    STACK_PUSH(a, last, depth, -1);
                    last = a, depth += 1, limit = ss_ilg(a - first);
                } else {
                    first = a, limit = -1;
                }
            } else {
                if(1 < (last - a)) {
                    STACK_PUSH(first, a, depth + 1, ss_ilg(a - first));
                    first = a, limit = -1;
                } else {
                    last = a, depth += 1, limit = ss_ilg(a - first);
                }
            }
            continue;
        }

        /* choose pivot */
        a = ss_pivot(Td, PA, first, last);
        v = Td[PA[*a]];
        SWAP(*first, *a);

        /* partition */
        for(b = first; (++b < last) && ((x = Td[PA[*b]]) == v);) { }
        if(((a = b) < last) && (x < v)) {
            for(; (++b < last) && ((x = Td[PA[*b]]) <= v);) {
                if(x == v) { SWAP(*b, *a); ++a; }
            }
        }
        for(c = last; (b < --c) && ((x = Td[PA[*c]]) == v);) { }
        if((b < (d = c)) && (x > v)) {
            for(; (b < --c) && ((x = Td[PA[*c]]) >= v);) {
                if(x == v) { SWAP(*c, *d); --d; }
            }
        }
        for(; b < c;) {
            SWAP(*b, *c);
            for(; (++b < c) && ((x = Td[PA[*b]]) <= v);) {
                if(x == v) { SWAP(*b, *a); ++a; }
            }
            for(; (b < --c) && ((x = Td[PA[*c]]) >= v);) {
                if(x == v) { SWAP(*c, *d); --d; }
            }
        }

        if(a <= d) {
            c = b - 1;

            if((s = a - first) > (t = b - a)) { s = t; }
            for(e = first, f = b - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
            if((s = d - c) > (t = last - d - 1)) { s = t; }
            for(e = b, f = last - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }

            a = first + (b - a), c = last - (d - c);
            b = (v <= Td[PA[*a] - 1]) ? a : ss_partition(PA, a, c, depth);

            if((a - first) <= (last - c)) {
                if((last - c) <= (c - b)) {
                    STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
                    STACK_PUSH(c, last, depth, limit);
                    last = a;
                } else if((a - first) <= (c - b)) {
                    STACK_PUSH(c, last, depth, limit);
                    STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
                    last = a;
                } else {
                    STACK_PUSH(c, last, depth, limit);
                    STACK_PUSH(first, a, depth, limit);
                    first = b, last = c, depth += 1, limit = ss_ilg(c - b);
                }
            } else {
                if((a - first) <= (c - b)) {
                    STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
                    STACK_PUSH(first, a, depth, limit);
                    first = c;
                } else if((last - c) <= (c - b)) {
                    STACK_PUSH(first, a, depth, limit);
                    STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
                    first = c;
                } else {
                    STACK_PUSH(first, a, depth, limit);
                    STACK_PUSH(c, last, depth, limit);
                    first = b, last = c, depth += 1, limit = ss_ilg(c - b);
                }
            }
        } else {
            limit += 1;
            if(Td[PA[*first] - 1] < v) {
                first = ss_partition(PA, first, last, depth);
                limit = ss_ilg(last - first);
            }
            depth += 1;
        }
    }
#undef STACK_SIZE
}

#endif /* (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE) */


/*---------------------------------------------------------------------------*/

#if SS_BLOCKSIZE != 0

static INLINE
void
ss_blockswap(int *a, int *b, int n) {
    int t;
    for(; 0 < n; --n, ++a, ++b) {
        t = *a, *a = *b, *b = t;
    }
}

static INLINE
void
ss_rotate(int *first, int *middle, int *last) {
    int *a, *b, t;
    int l, r;
    l = middle - first, r = last - middle;
    for(; (0 < l) && (0 < r);) {
        if(l == r) { ss_blockswap(first, middle, l); break; }
        if(l < r) {
            a = last - 1, b = middle - 1;
            t = *a;
            do {
                *a-- = *b, *b-- = *a;
                if(b < first) {
                    *a = t;
                    last = a;
                    if((r -= l + 1) <= l) { break; }
                    a -= 1, b = middle - 1;
                    t = *a;
                }
            } while(1);
        } else {
            a = first, b = middle;
            t = *a;
            do {
                *a++ = *b, *b++ = *a;
                if(last <= b) {
                    *a = t;
                    first = a + 1;
                    if((l -= r + 1) <= r) { break; }
                    a += 1, b = middle;
                    t = *a;
                }
            } while(1);
        }
    }
}


/*---------------------------------------------------------------------------*/

static
void
ss_inplacemerge(const unsigned char *T, const int *PA,
                                int *first, int *middle, int *last,
                                int depth) {
    const int *p;
    int *a, *b;
    int len, half;
    int q, r;
    int x;

    for(;;) {
        if(*(last - 1) < 0) { x = 1; p = PA + ~*(last - 1); }
        else                { x = 0; p = PA +  *(last - 1); }
        for(a = first, len = middle - first, half = len >> 1, r = -1;
                0 < len;
                len = half, half >>= 1) {
            b = a + half;
            q = ss_compare(T, PA + ((0 <= *b) ? *b : ~*b), p, depth);
            if(q < 0) {
                a = b + 1;
                half -= (len & 1) ^ 1;
            } else {
                r = q;
            }
        }
        if(a < middle) {
            if(r == 0) { *a = ~*a; }
            ss_rotate(a, middle, last);
            last -= middle - a;
            middle = a;
            if(first == middle) { break; }
        }
        --last;
        if(x != 0) { while(*--last < 0) { } }
        if(middle == last) { break; }
    }
}


/*---------------------------------------------------------------------------*/

/* Merge-forward with internal buffer. */
static
void
ss_mergeforward(const unsigned char *T, const int *PA,
                                int *first, int *middle, int *last,
                                int *buf, int depth) {
    int *a, *b, *c, *bufend;
    int t;
    int r;

    bufend = buf + (middle - first) - 1;
    ss_blockswap(buf, first, middle - first);

    for(t = *(a = first), b = buf, c = middle;;) {
        r = ss_compare(T, PA + *b, PA + *c, depth);
        if(r < 0) {
            do {
                *a++ = *b;
                if(bufend <= b) { *bufend = t; return; }
                *b++ = *a;
            } while(*b < 0);
        } else if(r > 0) {
            do {
                *a++ = *c, *c++ = *a;
                if(last <= c) {
                    while(b < bufend) { *a++ = *b, *b++ = *a; }
                    *a = *b, *b = t;
                    return;
                }
            } while(*c < 0);
        } else {
            *c = ~*c;
            do {
                *a++ = *b;
                if(bufend <= b) { *bufend = t; return; }
                *b++ = *a;
            } while(*b < 0);

            do {
                *a++ = *c, *c++ = *a;
                if(last <= c) {
                    while(b < bufend) { *a++ = *b, *b++ = *a; }
                    *a = *b, *b = t;
                    return;
                }
            } while(*c < 0);
        }
    }
}

/* Merge-backward with internal buffer. */
static
void
ss_mergebackward(const unsigned char *T, const int *PA,
                                 int *first, int *middle, int *last,
                                 int *buf, int depth) {
    const int *p1, *p2;
    int *a, *b, *c, *bufend;
    int t;
    int r;
    int x;

    bufend = buf + (last - middle) - 1;
    ss_blockswap(buf, middle, last - middle);

    x = 0;
    if(*bufend < 0)       { p1 = PA + ~*bufend; x |= 1; }
    else                  { p1 = PA +  *bufend; }
    if(*(middle - 1) < 0) { p2 = PA + ~*(middle - 1); x |= 2; }
    else                  { p2 = PA +  *(middle - 1); }
    for(t = *(a = last - 1), b = bufend, c = middle - 1;;) {
        r = ss_compare(T, p1, p2, depth);
        if(0 < r) {
            if(x & 1) { do { *a-- = *b, *b-- = *a; } while(*b < 0); x ^= 1; }
            *a-- = *b;
            if(b <= buf) { *buf = t; break; }
            *b-- = *a;
            if(*b < 0) { p1 = PA + ~*b; x |= 1; }
            else       { p1 = PA +  *b; }
        } else if(r < 0) {
            if(x & 2) { do { *a-- = *c, *c-- = *a; } while(*c < 0); x ^= 2; }
            *a-- = *c, *c-- = *a;
            if(c < first) {
                while(buf < b) { *a-- = *b, *b-- = *a; }
                *a = *b, *b = t;
                break;
            }
            if(*c < 0) { p2 = PA + ~*c; x |= 2; }
            else       { p2 = PA +  *c; }
        } else {
            if(x & 1) { do { *a-- = *b, *b-- = *a; } while(*b < 0); x ^= 1; }
            *a-- = ~*b;
            if(b <= buf) { *buf = t; break; }
            *b-- = *a;
            if(x & 2) { do { *a-- = *c, *c-- = *a; } while(*c < 0); x ^= 2; }
            *a-- = *c, *c-- = *a;
            if(c < first) {
                while(buf < b) { *a-- = *b, *b-- = *a; }
                *a = *b, *b = t;
                break;
            }
            if(*b < 0) { p1 = PA + ~*b; x |= 1; }
            else       { p1 = PA +  *b; }
            if(*c < 0) { p2 = PA + ~*c; x |= 2; }
            else       { p2 = PA +  *c; }
        }
    }
}

/* D&C based merge. */
static
void
ss_swapmerge(const unsigned char *T, const int *PA,
                         int *first, int *middle, int *last,
                         int *buf, int bufsize, int depth) {
#define STACK_SIZE SS_SMERGE_STACKSIZE
#define GETIDX(a) ((0 <= (a)) ? (a) : (~(a)))
#define MERGE_CHECK(a, b, c)\
    do {\
        if(((c) & 1) ||\
             (((c) & 2) && (ss_compare(T, PA + GETIDX(*((a) - 1)), PA + *(a), depth) == 0))) {\
            *(a) = ~*(a);\
        }\
        if(((c) & 4) && ((ss_compare(T, PA + GETIDX(*((b) - 1)), PA + *(b), depth) == 0))) {\
            *(b) = ~*(b);\
        }\
    } while(0)
    struct { int *a, *b, *c; int d; } stack[STACK_SIZE];
    int *l, *r, *lm, *rm;
    int m, len, half;
    int ssize;
    int check, next;

    for(check = 0, ssize = 0;;) {
        if((last - middle) <= bufsize) {
            if((first < middle) && (middle < last)) {
                ss_mergebackward(T, PA, first, middle, last, buf, depth);
            }
            MERGE_CHECK(first, last, check);
            STACK_POP(first, middle, last, check);
            continue;
        }

        if((middle - first) <= bufsize) {
            if(first < middle) {
                ss_mergeforward(T, PA, first, middle, last, buf, depth);
            }
            MERGE_CHECK(first, last, check);
            STACK_POP(first, middle, last, check);
            continue;
        }

        for(m = 0, len = MIN(middle - first, last - middle), half = len >> 1;
                0 < len;
                len = half, half >>= 1) {
            if(ss_compare(T, PA + GETIDX(*(middle + m + half)),
                                             PA + GETIDX(*(middle - m - half - 1)), depth) < 0) {
                m += half + 1;
                half -= (len & 1) ^ 1;
            }
        }

        if(0 < m) {
            lm = middle - m, rm = middle + m;
            ss_blockswap(lm, middle, m);
            l = r = middle, next = 0;
            if(rm < last) {
                if(*rm < 0) {
                    *rm = ~*rm;
                    if(first < lm) { for(; *--l < 0;) { } next |= 4; }
                    next |= 1;
                } else if(first < lm) {
                    for(; *r < 0; ++r) { }
                    next |= 2;
                }
            }

            if((l - first) <= (last - r)) {
                STACK_PUSH(r, rm, last, (next & 3) | (check & 4));
                middle = lm, last = l, check = (check & 3) | (next & 4);
            } else {
                if((next & 2) && (r == middle)) { next ^= 6; }
                STACK_PUSH(first, lm, l, (check & 3) | (next & 4));
                first = r, middle = rm, check = (next & 3) | (check & 4);
            }
        } else {
            if(ss_compare(T, PA + GETIDX(*(middle - 1)), PA + *middle, depth) == 0) {
                *middle = ~*middle;
            }
            MERGE_CHECK(first, last, check);
            STACK_POP(first, middle, last, check);
        }
    }
#undef STACK_SIZE
}

#endif /* SS_BLOCKSIZE != 0 */


/*---------------------------------------------------------------------------*/

/* Substring sort */
static
void
sssort(const unsigned char *T, const int *PA,
             int *first, int *last,
             int *buf, int bufsize,
             int depth, int n, int lastsuffix) {
    int *a;
#if SS_BLOCKSIZE != 0
    int *b, *middle, *curbuf;
    int j, k, curbufsize, limit;
#endif
    int i;

    if(lastsuffix != 0) { ++first; }

#if SS_BLOCKSIZE == 0
    ss_mintrosort(T, PA, first, last, depth);
#else
    if((bufsize < SS_BLOCKSIZE) &&
            (bufsize < (last - first)) &&
            (bufsize < (limit = ss_isqrt(last - first)))) {
        if(SS_BLOCKSIZE < limit) { limit = SS_BLOCKSIZE; }
        buf = middle = last - limit, bufsize = limit;
    } else {
        middle = last, limit = 0;
    }
    for(a = first, i = 0; SS_BLOCKSIZE < (middle - a); a += SS_BLOCKSIZE, ++i) {
#if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
        ss_mintrosort(T, PA, a, a + SS_BLOCKSIZE, depth);
#elif 1 < SS_BLOCKSIZE
        ss_insertionsort(T, PA, a, a + SS_BLOCKSIZE, depth);
#endif
        curbufsize = last - (a + SS_BLOCKSIZE);
        curbuf = a + SS_BLOCKSIZE;
        if(curbufsize <= bufsize) { curbufsize = bufsize, curbuf = buf; }
        for(b = a, k = SS_BLOCKSIZE, j = i; j & 1; b -= k, k <<= 1, j >>= 1) {
            ss_swapmerge(T, PA, b - k, b, b + k, curbuf, curbufsize, depth);
        }
    }
#if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
    ss_mintrosort(T, PA, a, middle, depth);
#elif 1 < SS_BLOCKSIZE
    ss_insertionsort(T, PA, a, middle, depth);
#endif
    for(k = SS_BLOCKSIZE; i != 0; k <<= 1, i >>= 1) {
        if(i & 1) {
            ss_swapmerge(T, PA, a - k, a, middle, buf, bufsize, depth);
            a -= k;
        }
    }
    if(limit != 0) {
#if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
        ss_mintrosort(T, PA, middle, last, depth);
#elif 1 < SS_BLOCKSIZE
        ss_insertionsort(T, PA, middle, last, depth);
#endif
        ss_inplacemerge(T, PA, first, middle, last, depth);
    }
#endif

    if(lastsuffix != 0) {
        /* Insert last type B* suffix. */
        int PAi[2]; PAi[0] = PA[*(first - 1)], PAi[1] = n - 2;
        for(a = first, i = *(first - 1);
                (a < last) && ((*a < 0) || (0 < ss_compare(T, &(PAi[0]), PA + *a, depth)));
                ++a) {
            *(a - 1) = *a;
        }
        *(a - 1) = i;
    }
}


/*---------------------------------------------------------------------------*/

static INLINE
int
tr_ilg(int n) {
    return (n & 0xffff0000) ?
                    ((n & 0xff000000) ?
                        24 + lg_table[(n >> 24) & 0xff] :
                        16 + lg_table[(n >> 16) & 0xff]) :
                    ((n & 0x0000ff00) ?
                         8 + lg_table[(n >>  8) & 0xff] :
                         0 + lg_table[(n >>  0) & 0xff]);
}


/*---------------------------------------------------------------------------*/

/* Simple insertionsort for small size groups. */
static
void
tr_insertionsort(const int *ISAd, int *first, int *last) {
    int *a, *b;
    int t, r;

    for(a = first + 1; a < last; ++a) {
        for(t = *a, b = a - 1; 0 > (r = ISAd[t] - ISAd[*b]);) {
            do { *(b + 1) = *b; } while((first <= --b) && (*b < 0));
            if(b < first) { break; }
        }
        if(r == 0) { *b = ~*b; }
        *(b + 1) = t;
    }
}


/*---------------------------------------------------------------------------*/

static INLINE
void
tr_fixdown(const int *ISAd, int *SA, int i, int size) {
    int j, k;
    int v;
    int c, d, e;

    for(v = SA[i], c = ISAd[v]; (j = 2 * i + 1) < size; SA[i] = SA[k], i = k) {
        d = ISAd[SA[k = j++]];
        if(d < (e = ISAd[SA[j]])) { k = j; d = e; }
        if(d <= c) { break; }
    }
    SA[i] = v;
}

/* Simple top-down heapsort. */
static
void
tr_heapsort(const int *ISAd, int *SA, int size) {
    int i, m;
    int t;

    m = size;
    if((size % 2) == 0) {
        m--;
        if(ISAd[SA[m / 2]] < ISAd[SA[m]]) { SWAP(SA[m], SA[m / 2]); }
    }

    for(i = m / 2 - 1; 0 <= i; --i) { tr_fixdown(ISAd, SA, i, m); }
    if((size % 2) == 0) { SWAP(SA[0], SA[m]); tr_fixdown(ISAd, SA, 0, m); }
    for(i = m - 1; 0 < i; --i) {
        t = SA[0], SA[0] = SA[i];
        tr_fixdown(ISAd, SA, 0, i);
        SA[i] = t;
    }
}


/*---------------------------------------------------------------------------*/

/* Returns the median of three elements. */
static INLINE
int *
tr_median3(const int *ISAd, int *v1, int *v2, int *v3) {
    int *t;
    if(ISAd[*v1] > ISAd[*v2]) { SWAP(v1, v2); }
    if(ISAd[*v2] > ISAd[*v3]) {
        if(ISAd[*v1] > ISAd[*v3]) { return v1; }
        else { return v3; }
    }
    return v2;
}

/* Returns the median of five elements. */
static INLINE
int *
tr_median5(const int *ISAd,
                     int *v1, int *v2, int *v3, int *v4, int *v5) {
    int *t;
    if(ISAd[*v2] > ISAd[*v3]) { SWAP(v2, v3); }
    if(ISAd[*v4] > ISAd[*v5]) { SWAP(v4, v5); }
    if(ISAd[*v2] > ISAd[*v4]) { SWAP(v2, v4); SWAP(v3, v5); }
    if(ISAd[*v1] > ISAd[*v3]) { SWAP(v1, v3); }
    if(ISAd[*v1] > ISAd[*v4]) { SWAP(v1, v4); SWAP(v3, v5); }
    if(ISAd[*v3] > ISAd[*v4]) { return v4; }
    return v3;
}

/* Returns the pivot element. */
static INLINE
int *
tr_pivot(const int *ISAd, int *first, int *last) {
    int *middle;
    int t;

    t = last - first;
    middle = first + t / 2;

    if(t <= 512) {
        if(t <= 32) {
            return tr_median3(ISAd, first, middle, last - 1);
        } else {
            t >>= 2;
            return tr_median5(ISAd, first, first + t, middle, last - 1 - t, last - 1);
        }
    }
    t >>= 3;
    first  = tr_median3(ISAd, first, first + t, first + (t << 1));
    middle = tr_median3(ISAd, middle - t, middle, middle + t);
    last   = tr_median3(ISAd, last - 1 - (t << 1), last - 1 - t, last - 1);
    return tr_median3(ISAd, first, middle, last);
}


/*---------------------------------------------------------------------------*/

typedef struct _trbudget_t trbudget_t;
struct _trbudget_t {
    int chance;
    int remain;
    int incval;
    int count;
};

static INLINE
void
trbudget_init(trbudget_t *budget, int chance, int incval) {
    budget->chance = chance;
    budget->remain = budget->incval = incval;
}

static INLINE
int
trbudget_check(trbudget_t *budget, int size) {
    if(size <= budget->remain) { budget->remain -= size; return 1; }
    if(budget->chance == 0) { budget->count += size; return 0; }
    budget->remain += budget->incval - size;
    budget->chance -= 1;
    return 1;
}


/*---------------------------------------------------------------------------*/

static INLINE
void
tr_partition(const int *ISAd,
                         int *first, int *middle, int *last,
                         int **pa, int **pb, int v) {
    int *a, *b, *c, *d, *e, *f;
    int t, s;
    int x = 0;

    for(b = middle - 1; (++b < last) && ((x = ISAd[*b]) == v);) { }
    if(((a = b) < last) && (x < v)) {
        for(; (++b < last) && ((x = ISAd[*b]) <= v);) {
            if(x == v) { SWAP(*b, *a); ++a; }
        }
    }
    for(c = last; (b < --c) && ((x = ISAd[*c]) == v);) { }
    if((b < (d = c)) && (x > v)) {
        for(; (b < --c) && ((x = ISAd[*c]) >= v);) {
            if(x == v) { SWAP(*c, *d); --d; }
        }
    }
    for(; b < c;) {
        SWAP(*b, *c);
        for(; (++b < c) && ((x = ISAd[*b]) <= v);) {
            if(x == v) { SWAP(*b, *a); ++a; }
        }
        for(; (b < --c) && ((x = ISAd[*c]) >= v);) {
            if(x == v) { SWAP(*c, *d); --d; }
        }
    }

    if(a <= d) {
        c = b - 1;
        if((s = a - first) > (t = b - a)) { s = t; }
        for(e = first, f = b - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
        if((s = d - c) > (t = last - d - 1)) { s = t; }
        for(e = b, f = last - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
        first += (b - a), last -= (d - c);
    }
    *pa = first, *pb = last;
}

static
void
tr_copy(int *ISA, const int *SA,
                int *first, int *a, int *b, int *last,
                int depth) {
    /* sort suffixes of middle partition
         by using sorted order of suffixes of left and right partition. */
    int *c, *d, *e;
    int s, v;

    v = b - SA - 1;
    for(c = first, d = a - 1; c <= d; ++c) {
        if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
            *++d = s;
            ISA[s] = d - SA;
        }
    }
    for(c = last - 1, e = d + 1, d = b; e < d; --c) {
        if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
            *--d = s;
            ISA[s] = d - SA;
        }
    }
}

static
void
tr_partialcopy(int *ISA, const int *SA,
                             int *first, int *a, int *b, int *last,
                             int depth) {
    int *c, *d, *e;
    int s, v;
    int rank, lastrank, newrank = -1;

    v = b - SA - 1;
    lastrank = -1;
    for(c = first, d = a - 1; c <= d; ++c) {
        if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
            *++d = s;
            rank = ISA[s + depth];
            if(lastrank != rank) { lastrank = rank; newrank = d - SA; }
            ISA[s] = newrank;
        }
    }

    lastrank = -1;
    for(e = d; first <= e; --e) {
        rank = ISA[*e];
        if(lastrank != rank) { lastrank = rank; newrank = e - SA; }
        if(newrank != rank) { ISA[*e] = newrank; }
    }

    lastrank = -1;
    for(c = last - 1, e = d + 1, d = b; e < d; --c) {
        if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
            *--d = s;
            rank = ISA[s + depth];
            if(lastrank != rank) { lastrank = rank; newrank = d - SA; }
            ISA[s] = newrank;
        }
    }
}

static
void
tr_introsort(int *ISA, const int *ISAd,
                         int *SA, int *first, int *last,
                         trbudget_t *budget) {
#define STACK_SIZE TR_STACKSIZE
    struct { const int *a; int *b, *c; int d, e; }stack[STACK_SIZE];
    int *a, *b, *c;
    int t;
    int v, x = 0;
    int incr = ISAd - ISA;
    int limit, next;
    int ssize, trlink = -1;

    for(ssize = 0, limit = tr_ilg(last - first);;) {

        if(limit < 0) {
            if(limit == -1) {
                /* tandem repeat partition */
                tr_partition(ISAd - incr, first, first, last, &a, &b, last - SA - 1);

                /* update ranks */
                if(a < last) {
                    for(c = first, v = a - SA - 1; c < a; ++c) { ISA[*c] = v; }
                }
                if(b < last) {
                    for(c = a, v = b - SA - 1; c < b; ++c) { ISA[*c] = v; }
                }

                /* push */
                if(1 < (b - a)) {
                    STACK_PUSH5(NULL, a, b, 0, 0);
                    STACK_PUSH5(ISAd - incr, first, last, -2, trlink);
                    trlink = ssize - 2;
                }
                if((a - first) <= (last - b)) {
                    if(1 < (a - first)) {
                        STACK_PUSH5(ISAd, b, last, tr_ilg(last - b), trlink);
                        last = a, limit = tr_ilg(a - first);
                    } else if(1 < (last - b)) {
                        first = b, limit = tr_ilg(last - b);
                    } else {
                        STACK_POP5(ISAd, first, last, limit, trlink);
                    }
                } else {
                    if(1 < (last - b)) {
                        STACK_PUSH5(ISAd, first, a, tr_ilg(a - first), trlink);
                        first = b, limit = tr_ilg(last - b);
                    } else if(1 < (a - first)) {
                        last = a, limit = tr_ilg(a - first);
                    } else {
                        STACK_POP5(ISAd, first, last, limit, trlink);
                    }
                }
            } else if(limit == -2) {
                /* tandem repeat copy */
                a = stack[--ssize].b, b = stack[ssize].c;
                if(stack[ssize].d == 0) {
                    tr_copy(ISA, SA, first, a, b, last, ISAd - ISA);
                } else {
                    if(0 <= trlink) { stack[trlink].d = -1; }
                    tr_partialcopy(ISA, SA, first, a, b, last, ISAd - ISA);
                }
                STACK_POP5(ISAd, first, last, limit, trlink);
            } else {
                /* sorted partition */
                if(0 <= *first) {
                    a = first;
                    do { ISA[*a] = a - SA; } while((++a < last) && (0 <= *a));
                    first = a;
                }
                if(first < last) {
                    a = first; do { *a = ~*a; } while(*++a < 0);
                    next = (ISA[*a] != ISAd[*a]) ? tr_ilg(a - first + 1) : -1;
                    if(++a < last) { for(b = first, v = a - SA - 1; b < a; ++b) { ISA[*b] = v; } }

                    /* push */
                    if(trbudget_check(budget, a - first)) {
                        if((a - first) <= (last - a)) {
                            STACK_PUSH5(ISAd, a, last, -3, trlink);
                            ISAd += incr, last = a, limit = next;
                        } else {
                            if(1 < (last - a)) {
                                STACK_PUSH5(ISAd + incr, first, a, next, trlink);
                                first = a, limit = -3;
                            } else {
                                ISAd += incr, last = a, limit = next;
                            }
                        }
                    } else {
                        if(0 <= trlink) { stack[trlink].d = -1; }
                        if(1 < (last - a)) {
                            first = a, limit = -3;
                        } else {
                            STACK_POP5(ISAd, first, last, limit, trlink);
                        }
                    }
                } else {
                    STACK_POP5(ISAd, first, last, limit, trlink);
                }
            }
            continue;
        }

        if((last - first) <= TR_INSERTIONSORT_THRESHOLD) {
            tr_insertionsort(ISAd, first, last);
            limit = -3;
            continue;
        }

        if(limit-- == 0) {
            tr_heapsort(ISAd, first, last - first);
            for(a = last - 1; first < a; a = b) {
                for(x = ISAd[*a], b = a - 1; (first <= b) && (ISAd[*b] == x); --b) { *b = ~*b; }
            }
            limit = -3;
            continue;
        }

        /* choose pivot */
        a = tr_pivot(ISAd, first, last);
        SWAP(*first, *a);
        v = ISAd[*first];

        /* partition */
        tr_partition(ISAd, first, first + 1, last, &a, &b, v);
        if((last - first) != (b - a)) {
            next = (ISA[*a] != v) ? tr_ilg(b - a) : -1;

            /* update ranks */
            for(c = first, v = a - SA - 1; c < a; ++c) { ISA[*c] = v; }
            if(b < last) { for(c = a, v = b - SA - 1; c < b; ++c) { ISA[*c] = v; } }

            /* push */
            if((1 < (b - a)) && (trbudget_check(budget, b - a))) {
                if((a - first) <= (last - b)) {
                    if((last - b) <= (b - a)) {
                        if(1 < (a - first)) {
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            STACK_PUSH5(ISAd, b, last, limit, trlink);
                            last = a;
                        } else if(1 < (last - b)) {
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            first = b;
                        } else {
                            ISAd += incr, first = a, last = b, limit = next;
                        }
                    } else if((a - first) <= (b - a)) {
                        if(1 < (a - first)) {
                            STACK_PUSH5(ISAd, b, last, limit, trlink);
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            last = a;
                        } else {
                            STACK_PUSH5(ISAd, b, last, limit, trlink);
                            ISAd += incr, first = a, last = b, limit = next;
                        }
                    } else {
                        STACK_PUSH5(ISAd, b, last, limit, trlink);
                        STACK_PUSH5(ISAd, first, a, limit, trlink);
                        ISAd += incr, first = a, last = b, limit = next;
                    }
                } else {
                    if((a - first) <= (b - a)) {
                        if(1 < (last - b)) {
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            STACK_PUSH5(ISAd, first, a, limit, trlink);
                            first = b;
                        } else if(1 < (a - first)) {
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            last = a;
                        } else {
                            ISAd += incr, first = a, last = b, limit = next;
                        }
                    } else if((last - b) <= (b - a)) {
                        if(1 < (last - b)) {
                            STACK_PUSH5(ISAd, first, a, limit, trlink);
                            STACK_PUSH5(ISAd + incr, a, b, next, trlink);
                            first = b;
                        } else {
                            STACK_PUSH5(ISAd, first, a, limit, trlink);
                            ISAd += incr, first = a, last = b, limit = next;
                        }
                    } else {
                        STACK_PUSH5(ISAd, first, a, limit, trlink);
                        STACK_PUSH5(ISAd, b, last, limit, trlink);
                        ISAd += incr, first = a, last = b, limit = next;
                    }
                }
            } else {
                if((1 < (b - a)) && (0 <= trlink)) { stack[trlink].d = -1; }
                if((a - first) <= (last - b)) {
                    if(1 < (a - first)) {
                        STACK_PUSH5(ISAd, b, last, limit, trlink);
                        last = a;
                    } else if(1 < (last - b)) {
                        first = b;
                    } else {
                        STACK_POP5(ISAd, first, last, limit, trlink);
                    }
                } else {
                    if(1 < (last - b)) {
                        STACK_PUSH5(ISAd, first, a, limit, trlink);
                        first = b;
                    } else if(1 < (a - first)) {
                        last = a;
                    } else {
                        STACK_POP5(ISAd, first, last, limit, trlink);
                    }
                }
            }
        } else {
            if(trbudget_check(budget, last - first)) {
                limit = tr_ilg(last - first), ISAd += incr;
            } else {
                if(0 <= trlink) { stack[trlink].d = -1; }
                STACK_POP5(ISAd, first, last, limit, trlink);
            }
        }
    }
#undef STACK_SIZE
}



/*---------------------------------------------------------------------------*/

/* Tandem repeat sort */
static
void
trsort(int *ISA, int *SA, int n, int depth) {
    int *ISAd;
    int *first, *last;
    trbudget_t budget;
    int t, skip, unsorted;

    trbudget_init(&budget, tr_ilg(n) * 2 / 3, n);
/*  trbudget_init(&budget, tr_ilg(n) * 3 / 4, n); */
    for(ISAd = ISA + depth; -n < *SA; ISAd += ISAd - ISA) {
        first = SA;
        skip = 0;
        unsorted = 0;
        do {
            if((t = *first) < 0) { first -= t; skip += t; }
            else {
                if(skip != 0) { *(first + skip) = skip; skip = 0; }
                last = SA + ISA[t] + 1;
                if(1 < (last - first)) {
                    budget.count = 0;
                    tr_introsort(ISA, ISAd, SA, first, last, &budget);
                    if(budget.count != 0) { unsorted += budget.count; }
                    else { skip = first - last; }
                } else if((last - first) == 1) {
                    skip = -1;
                }
                first = last;
            }
        } while(first < (SA + n));
        if(skip != 0) { *(first + skip) = skip; }
        if(unsorted == 0) { break; }
    }
}


/*---------------------------------------------------------------------------*/

/* Sorts suffixes of type B*. */
static
int
sort_typeBstar(const unsigned char *T, int *SA,
                             int *bucket_A, int *bucket_B,
                             int n) {
    int *PAb, *ISAb, *buf;
#ifdef _OPENMP
    int *curbuf;
    int l;
#endif
    int i, j, k, t, m, bufsize;
    int c0, c1;
#ifdef _OPENMP
    int d0, d1;
    int tmp;
#endif

    /* Initialize bucket arrays. */
    for(i = 0; i < BUCKET_A_SIZE; ++i) { bucket_A[i] = 0; }
    for(i = 0; i < BUCKET_B_SIZE; ++i) { bucket_B[i] = 0; }

    /* Count the number of occurrences of the first one or two characters of each
         type A, B and B* suffix. Moreover, store the beginning position of all
         type B* suffixes into the array SA. */
    for(i = n - 1, m = n, c0 = T[n - 1]; 0 <= i;) {
        /* type A suffix. */
        do { ++BUCKET_A(c1 = c0); } while((0 <= --i) && ((c0 = T[i]) >= c1));
        if(0 <= i) {
            /* type B* suffix. */
            ++BUCKET_BSTAR(c0, c1);
            SA[--m] = i;
            /* type B suffix. */
            for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) <= c1); --i, c1 = c0) {
                ++BUCKET_B(c0, c1);
            }
        }
    }
    m = n - m;
/*
note:
    A type B* suffix is lexicographically smaller than a type B suffix that
    begins with the same first two characters.
*/

    /* Calculate the index of start/end point of each bucket. */
    for(c0 = 0, i = 0, j = 0; c0 < ALPHABET_SIZE; ++c0) {
        t = i + BUCKET_A(c0);
        BUCKET_A(c0) = i + j; /* start point */
        i = t + BUCKET_B(c0, c0);
        for(c1 = c0 + 1; c1 < ALPHABET_SIZE; ++c1) {
            j += BUCKET_BSTAR(c0, c1);
            BUCKET_BSTAR(c0, c1) = j; /* end point */
            i += BUCKET_B(c0, c1);
        }
    }

    if(0 < m) {
        /* Sort the type B* suffixes by their first two characters. */
        PAb = SA + n - m; ISAb = SA + m;
        for(i = m - 2; 0 <= i; --i) {
            t = PAb[i], c0 = T[t], c1 = T[t + 1];
            SA[--BUCKET_BSTAR(c0, c1)] = i;
        }
        t = PAb[m - 1], c0 = T[t], c1 = T[t + 1];
        SA[--BUCKET_BSTAR(c0, c1)] = m - 1;

        /* Sort the type B* substrings using sssort. */
#ifdef _OPENMP
        tmp = omp_get_max_threads();
        buf = SA + m, bufsize = (n - (2 * m)) / tmp;
        c0 = ALPHABET_SIZE - 2, c1 = ALPHABET_SIZE - 1, j = m;
#pragma omp parallel default(shared) private(curbuf, k, l, d0, d1, tmp)
        {
            tmp = omp_get_thread_num();
            curbuf = buf + tmp * bufsize;
            k = 0;
            for(;;) {
                #pragma omp critical(sssort_lock)
                {
                    if(0 < (l = j)) {
                        d0 = c0, d1 = c1;
                        do {
                            k = BUCKET_BSTAR(d0, d1);
                            if(--d1 <= d0) {
                                d1 = ALPHABET_SIZE - 1;
                                if(--d0 < 0) { break; }
                            }
                        } while(((l - k) <= 1) && (0 < (l = k)));
                        c0 = d0, c1 = d1, j = k;
                    }
                }
                if(l == 0) { break; }
                sssort(T, PAb, SA + k, SA + l,
                             curbuf, bufsize, 2, n, *(SA + k) == (m - 1));
            }
        }
#else
        buf = SA + m, bufsize = n - (2 * m);
        for(c0 = ALPHABET_SIZE - 2, j = m; 0 < j; --c0) {
            for(c1 = ALPHABET_SIZE - 1; c0 < c1; j = i, --c1) {
                i = BUCKET_BSTAR(c0, c1);
                if(1 < (j - i)) {
                    sssort(T, PAb, SA + i, SA + j,
                                 buf, bufsize, 2, n, *(SA + i) == (m - 1));
                }
            }
        }
#endif

        /* Compute ranks of type B* substrings. */
        for(i = m - 1; 0 <= i; --i) {
            if(0 <= SA[i]) {
                j = i;
                do { ISAb[SA[i]] = i; } while((0 <= --i) && (0 <= SA[i]));
                SA[i + 1] = i - j;
                if(i <= 0) { break; }
            }
            j = i;
            do { ISAb[SA[i] = ~SA[i]] = j; } while(SA[--i] < 0);
            ISAb[SA[i]] = j;
        }

        /* Construct the inverse suffix array of type B* suffixes using trsort. */
        trsort(ISAb, SA, m, 1);

        /* Set the sorted order of tyoe B* suffixes. */
        for(i = n - 1, j = m, c0 = T[n - 1]; 0 <= i;) {
            for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) >= c1); --i, c1 = c0) { }
            if(0 <= i) {
                t = i;
                for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) <= c1); --i, c1 = c0) { }
                SA[ISAb[--j]] = ((t == 0) || (1 < (t - i))) ? t : ~t;
            }
        }

        /* Calculate the index of start/end point of each bucket. */
        BUCKET_B(ALPHABET_SIZE - 1, ALPHABET_SIZE - 1) = n; /* end point */
        for(c0 = ALPHABET_SIZE - 2, k = m - 1; 0 <= c0; --c0) {
            i = BUCKET_A(c0 + 1) - 1;
            for(c1 = ALPHABET_SIZE - 1; c0 < c1; --c1) {
                t = i - BUCKET_B(c0, c1);
                BUCKET_B(c0, c1) = i; /* end point */

                /* Move all type B* suffixes to the correct position. */
                for(i = t, j = BUCKET_BSTAR(c0, c1);
                        j <= k;
                        --i, --k) { SA[i] = SA[k]; }
            }
            BUCKET_BSTAR(c0, c0 + 1) = i - BUCKET_B(c0, c0) + 1; /* start point */
            BUCKET_B(c0, c0) = i; /* end point */
        }
    }

    return m;
}

/* Constructs the suffix array by using the sorted order of type B* suffixes. */
static
void
construct_SA(const unsigned char *T, int *SA,
                         int *bucket_A, int *bucket_B,
                         int n, int m) {
    int *i, *j, *k;
    int s;
    int c0, c1, c2;

    if(0 < m) {
        /* Construct the sorted order of type B suffixes by using
             the sorted order of type B* suffixes. */
        for(c1 = ALPHABET_SIZE - 2; 0 <= c1; --c1) {
            /* Scan the suffix array from right to left. */
            for(i = SA + BUCKET_BSTAR(c1, c1 + 1),
                    j = SA + BUCKET_A(c1 + 1) - 1, k = NULL, c2 = -1;
                    i <= j;
                    --j) {
                if(0 < (s = *j)) {
                    assert(T[s] == c1);
                    assert(((s + 1) < n) && (T[s] <= T[s + 1]));
                    assert(T[s - 1] <= T[s]);
                    *j = ~s;
                    c0 = T[--s];
                    if((0 < s) && (T[s - 1] > c0)) { s = ~s; }
                    if(c0 != c2) {
                        if(0 <= c2) { BUCKET_B(c2, c1) = k - SA; }
                        k = SA + BUCKET_B(c2 = c0, c1);
                    }
                    assert(k < j);
                    *k-- = s;
                } else {
                    assert(((s == 0) && (T[s] == c1)) || (s < 0));
                    *j = ~s;
                }
            }
        }
    }

    /* Construct the suffix array by using
         the sorted order of type B suffixes. */
    k = SA + BUCKET_A(c2 = T[n - 1]);
    *k++ = (T[n - 2] < c2) ? ~(n - 1) : (n - 1);
    /* Scan the suffix array from left to right. */
    for(i = SA, j = SA + n; i < j; ++i) {
        if(0 < (s = *i)) {
            assert(T[s - 1] >= T[s]);
            c0 = T[--s];
            if((s == 0) || (T[s - 1] < c0)) { s = ~s; }
            if(c0 != c2) {
                BUCKET_A(c2) = k - SA;
                k = SA + BUCKET_A(c2 = c0);
            }
            assert(i < k);
            *k++ = s;
        } else {
            assert(s < 0);
            *i = ~s;
        }
    }
}

/* Constructs the burrows-wheeler transformed string directly
     by using the sorted order of type B* suffixes. */
static
int
construct_BWT(const unsigned char *T, int *SA,
                            int *bucket_A, int *bucket_B,
                            int n, int m) {
    int *i, *j, *k, *orig;
    int s;
    int c0, c1, c2;

    if(0 < m) {
        /* Construct the sorted order of type B suffixes by using
             the sorted order of type B* suffixes. */
        for(c1 = ALPHABET_SIZE - 2; 0 <= c1; --c1) {
            /* Scan the suffix array from right to left. */
            for(i = SA + BUCKET_BSTAR(c1, c1 + 1),
                    j = SA + BUCKET_A(c1 + 1) - 1, k = NULL, c2 = -1;
                    i <= j;
                    --j) {
                if(0 < (s = *j)) {
                    assert(T[s] == c1);
                    assert(((s + 1) < n) && (T[s] <= T[s + 1]));
                    assert(T[s - 1] <= T[s]);
                    c0 = T[--s];
                    *j = ~((int)c0);
                    if((0 < s) && (T[s - 1] > c0)) { s = ~s; }
                    if(c0 != c2) {
                        if(0 <= c2) { BUCKET_B(c2, c1) = k - SA; }
                        k = SA + BUCKET_B(c2 = c0, c1);
                    }
                    assert(k < j);
                    *k-- = s;
                } else if(s != 0) {
                    *j = ~s;
#ifndef NDEBUG
                } else {
                    assert(T[s] == c1);
#endif
                }
            }
        }
    }

    /* Construct the BWTed string by using
         the sorted order of type B suffixes. */
    k = SA + BUCKET_A(c2 = T[n - 1]);
    *k++ = (T[n - 2] < c2) ? ~((int)T[n - 2]) : (n - 1);
    /* Scan the suffix array from left to right. */
    for(i = SA, j = SA + n, orig = SA; i < j; ++i) {
        if(0 < (s = *i)) {
            assert(T[s - 1] >= T[s]);
            c0 = T[--s];
            *i = c0;
            if((0 < s) && (T[s - 1] < c0)) { s = ~((int)T[s - 1]); }
            if(c0 != c2) {
                BUCKET_A(c2) = k - SA;
                k = SA + BUCKET_A(c2 = c0);
            }
            assert(i < k);
            *k++ = s;
        } else if(s != 0) {
            *i = ~s;
        } else {
            orig = i;
        }
    }

    return orig - SA;
}


/*---------------------------------------------------------------------------*/

/*- Function -*/

int
bcm_divsufsort(const unsigned char *T, int *SA, int n) {
    int *bucket_A, *bucket_B;
    int m;
    int err = 0;

    /* Check arguments. */
    if((T == NULL) || (SA == NULL) || (n < 0)) { return -1; }
    else if(n == 0) { return 0; }
    else if(n == 1) { SA[0] = 0; return 0; }
    else if(n == 2) { m = (T[0] < T[1]); SA[m ^ 1] = 0, SA[m] = 1; return 0; }

    bucket_A = (int *)malloc(BUCKET_A_SIZE * sizeof(int));
    bucket_B = (int *)malloc(BUCKET_B_SIZE * sizeof(int));

    /* Suffixsort. */
    if((bucket_A != NULL) && (bucket_B != NULL)) {
        m = sort_typeBstar(T, SA, bucket_A, bucket_B, n);
        construct_SA(T, SA, bucket_A, bucket_B, n, m);
    } else {
        err = -2;
    }

    free(bucket_B);
    free(bucket_A);

    return err;
}

int
bcm_divbwt(const unsigned char *T, unsigned char *U, int *A, int n) {
    int *B;
    int *bucket_A, *bucket_B;
    int m, pidx, i;

    /* Check arguments. */
    if((T == NULL) || (U == NULL) || (n < 0)) { return -1; }
    else if(n <= 1) { if(n == 1) { U[0] = T[0]; } return n; }

    if((B = A) == NULL) { B = (int *)malloc((size_t)(n + 1) * sizeof(int)); }
    bucket_A = (int *)malloc(BUCKET_A_SIZE * sizeof(int));
    bucket_B = (int *)malloc(BUCKET_B_SIZE * sizeof(int));

    /* Burrows-Wheeler Transform. */
    if((B != NULL) && (bucket_A != NULL) && (bucket_B != NULL)) {
        m = sort_typeBstar(T, B, bucket_A, bucket_B, n);
        pidx = construct_BWT(T, B, bucket_A, bucket_B, n, m);

        /* Copy to output string. */
        U[0] = T[n - 1];
        for(i = 0; i < pidx; ++i) { U[i + 1] = (unsigned char)B[i]; }
        for(i += 1; i < n; ++i) { U[i] = (unsigned char)B[i]; }
        pidx += 1;
    } else {
        pidx = -2;
    }

    free(bucket_B);
    free(bucket_A);
    if(A == NULL) { free(B); }

    return pidx;
}

#endif // BCM_C
